Working with perforating guns, downhole tools, and explosive devices in wireline and perforating operations requires precision, discipline, and strict adherence to safety protocols. A single mistake during the arming or disarming process can lead to serious consequences, including misfires, unplanned detonations, or injuries.
I remember one cased hole wireline job where a routine perforation well operation could have gone wrong due to a misstep in the arming procedure. Everything seemed ready—wireline control systems, perforating guns, and pressure control equipment were all in place. But just before the explosive device was lowered into the well, a crucial safety step was skipped. That moment reinforced why strict adherence to arming and disarming procedures is non-negotiable.
Why Arming and Disarming Procedures Matter in Wireline Perforating
Handling explosive devices in wireline perforating services involves a high level of risk. Following the correct procedure ensures the elimination of stray voltage risks that could cause premature detonation and allows safe handling of perforating guns during rig-up and transportation. It also prevents misfires, which can lead to fishing wire line operations or stuck tools, and ensures compliance with wireline service provider safety regulations.
For any wireline company, these safety steps are critical in cased hole logging, well perforation, and pipe recovery operations.
How to Safely Arm Explosive Devices in Wireline Perforating
All explosive devices must be armed by the Engineer in charge on location. Before the arming process, the Engineer must wear the safety key on an armband, ensuring it remains visible outside the wireline unit.
The arming process begins by ensuring all grounding cables are connected and that a stray voltage check has been completed. The area must be cleared of unnecessary personnel before proceeding. The gun circuit is then checked using an approved blaster’s meter, followed by the attachment of the collar locator (CCL) and cable head to the gun assembly. The proper detonator is placed in a safety tube, and the detonator leads are checked for proper resistance before being shunted.
Before connecting the detonator to the gun wires, the stripped gun wire is touched to the gun body to confirm no voltage is present. Once verified, the gun wires and prima cord are trimmed to the correct length. The ground leg of the detonator is attached to the gun ground wire, followed by connecting the hot leg of the detonator to the gun through wire. Finally, the detonator is removed from the safety tube and attached to the prima cord before securing the bull plug assembly to complete the arming process.
Once armed, the safety key must remain outside the unit until the armed explosive device has been lowered to at least 200 feet below the surface.
How to Disarm Explosive Devices in Wireline Perforating
When a perforating gun needs to be disarmed, whether due to a misfire or operational requirement, the process is just as critical as the arming procedure. Before starting, the Engineer must wear the safety key visibly on an armband, and a tailgate safety meeting must be conducted to ensure all personnel involved understand the procedure.
At 200 feet, the safety key is transferred to the lead operator, who displays it outside the unit. The area must be cleared of unnecessary personnel before retrieving the perforating gun from the well and securing it on stands. The bull plug assembly is then removed from the gun, and the prima cord is carefully cut from the detonator.
Once the detonator is placed in a safety tube, its wires are cut and immediately shunted together while remaining inside the safety tube. The detonator is then returned to a Type III magazine for safe storage. If the gun is to be transported, all guns must be disarmed, or the proper interrupter must be installed to ensure safe transport.
Why These Procedures Are Essential for Wireline Services Oil and Gas
Skipping or improperly executing arming and disarming procedures can result in unintentional detonations, failure in cased hole wireline operations, and potential injuries or equipment damage. Delays in production logging services and wireline well logging activities may also occur.
By maintaining a strict arming and disarming protocol, wireline service companies can safely conduct formation evaluation, well integrity testing, and wireline perforating services without risking personnel safety or operational efficiency.
Lessons Learned in Wireline Well Logging and Perforating Operations
Since implementing a standardized explosive device handling procedure, there has been a significant reduction in wireline perforating misfires and improved handling of wireline perforating guns and pressure control equipment. Compliance with wireline services market safety protocols has also strengthened, ensuring safe and efficient operations.
For any wireline service provider, ensuring that perforating systems, logging cables, and pressure control equipment are handled with precision and care is crucial.
In the wireline business, safety isn’t just a requirement—it’s the foundation of every successful operation.
Always follow the procedure. Always verify. Never take shortcuts.